While it sounds like the method has been found to upload any kind of learning directly to the brain as in the The Matrix, there are a few concerns with this most recent research. The first is the journal that published it. The journal Frontiers in Human Neuroscience has had to retract papers recently published for having bad data or computational errors. In addition, it is a journal that accepts payment for publishing research.
Another issue is a conflict of interest. The test subjects were all employees of HRL Laboratories and while none were directly supervised by the study investigators, the work was all completed at the company during normal business hours. Also, while the study states “the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.” HRL has applied for a patent for the technology used in the study which could be construed as having a vested interest in a positive outcome.
In an interview with George Dvorsky for Gizmodo, Mark S. George, a professor of psychiatry, radiology, and neurosciences at the Medical University of South Carolina, and editor-in-chief of the science journal Brain Stimulation, said it was “a small sample study in vulnerable employees, performed by scientists with patents pending that will be influenced by the outcome. This area is quite controversial, with positive studies getting published more frequently than failed trials, creating a publication bias. If there is an effect here in this study, the tDCS merely improved the ability of the subjects to learn. There was no transfer of information through the brain stimulation.”
A study published in the peer-reviewed journal Brain Stimulation in June 2015 looked at a much larger sample and found “Of 42 replicated cognitive outcome measures included in 59 analyses, tDCS has a significant effect on zero. There appears to be no reliable effect of tDCS on executive function, language, memory, or miscellaneous measures.”
Take a look at the discussion in the video below to learn more about tDCS and what it could mean for the future. For now, it remains questionable on what benefit it might have for learning.